浙江与加州沿岸上升流的季节和年际变化研究

发布时间：2018-06-14 23:26

本文选题：沿岸风生上升流 + 沿岸上升流指数　；参考：《南京信息工程大学》2016年硕士论文

【摘要】：世界上许多海域存在上升流,在大洋东西边界的沿岸上升流具有不同的生成机制,但绝大部分是因为沿岸风持续作用在海面上,由于埃克曼输运作用而产生。局地上升流将深层的营养物质带至表层,营养物质被表层的浮游生物所利用,同时给鱼类提供大量的饵料,这不仅增加了上升流区海洋生物多样性,还会因为形成上升流区渔场而具有重要的经济价值。因此,上升流的研究也就倍受关注,本文在上升流方面开展了如下研究：首先,改进了前人为了研究上升流特征而提出的上升流指数,主要改进的是利用实际风速作为初始资料,并考虑沿岸的倾斜角度,将水平输送值转化为垂直上升速度。该指数在表示上升流强度上更加的准确和直观,另外,减小站点之间的间隔更加有利于对整个沿岸上升流空间变化的研究。其次,采用改进的Bakun上升流指数表示沿岸上升流的强度,分别应用到浙江沿岸与加州沿岸的上升流区域。利用沿岸上升流指数与叶绿素浓度在时间尺度与空间尺度的高相关性验证了改进后的上升流指数更适用于两个沿岸上升流的研究。在两个沿岸区域,高的涡动能带正好位于沿岸上升流带上,这解释了上升流所引起的锋面不稳定可以调节沿岸叶绿素的浓度变化。最后,利用改进的上升流指数研究了两个沿岸上升流的季节变化、年际变化以及空间分布特征。浙江沿岸受到东亚季风的影响,在夏季当浙江沿岸海区被偏南风占据时,沿岸会产生季节性风生上升流,在空间上浙江沿岸上升流指数向北单调增长。研究还发现ENSO指数与上升流指数为滞后正相关以及PDO指数与上升流指数的负相关,这些说明了浙江沿岸上升流的长时间序列的变化特征。而在加州沿岸,上升流在3月份开始形成一直持续到10月到11月份。上升流指数与叶绿素浓度呈现出一致的夏季峰值结构。加州沿岸的叶绿素浓度的季节变化、年际变化、空间变化都与沿岸的上升流有关。ENSO与PDO分别与上升流指数呈现负相关,说明加州沿岸上升流长时间序列的变化与ENSO和PDO有关。
[Abstract]:There are upwelling in many sea areas in the world, and the coastal upwelling of the eastern and western border has different generating mechanisms, but most of it is caused by the continuous action of the coastal wind on the sea surface, due to the transport of the Ekman. At the same time, a large amount of food is provided to fish, which not only increases the marine biodiversity in the upwelling area, but also has important economic value for the formation of the upwelling area. Therefore, the study of the upwelling is also paid much attention. In this paper, the following studies have been carried out in the upwelling. First, the former has been improved to study the characteristics of the upwelling. The proposed upwelling index is mainly improved by using the actual wind speed as the initial data and considering the slope angle of the coast to convert the horizontal transport value to the vertical rising velocity. The index is more accurate and intuitive in representing the upwelling intensity. In addition, reducing the interval between the stations is more conducive to the rising flow of the whole coast. Secondly, the improved Bakun upwelling index is used to indicate the strength of the coastal upwelling, and applied to the upwelling region along the coast of Zhejiang and California respectively. The high correlation between the coastal upwelling index and the concentration of chlorophyll at the time scale and the spatial scale shows that the improved upwelling index is more suitable for two. In the study of coastal upwelling. In two coastal regions, the high eddy kinetic energy zone is located just along the coastal upwelling zone, which explains that the frontal instability caused by the upwelling can regulate the variation of the concentration of chlorophyll along the coast. Finally, the improved upwelling index is used to study the seasonal variation, interannual variation and space of the two coastal upwelling. Zhejiang coast is affected by the East Asian monsoon. In the summer, when the Zhejiang coastal area is occupied by the southern wind, the coast will produce seasonal wind upwelling, and the upwelling index of the Zhejiang coast is growing northward monotonically in space. The study also shows that the ENSO index and the upwelling index are the lag positive correlation and the PDO index and the upwelling index. The negative correlation shows the characteristics of the long time series of upwelling along the coast of Zhejiang. On the coast of California, the upwelling lasted from March to October to November. The upwelling index and the chlorophyll concentration showed the same peak summer peak structure. The seasonal variation of chlorophyll concentration in California coast, the interannual variation, and the empty space. The correlation between.ENSO and PDO in the coastal upwelling is negatively correlated with the upwelling index, indicating that the changes in the long time series of upwelling along the California coast are related to ENSO and PDO.
【学位授予单位】：南京信息工程大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P731.2

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